Carboxylic acids, including, for example, hydroxy-functional carboxylic acids, are useful in a number of industrially useful processes, including the synthesis of polyesters and polyamides. Such acids may be produced from fermentation. In order to improve fermentation performance, a base such as calcium hydroxide is often added to the reactor to neutralize the acid. To recover the acid, the fermentation broth is acidified with a mineral acid such as sulfuric acid. During this process, calcium sulfate (gypsum) is produced as a by-product, which must be removed and discarded. These additional processing steps raise the cost of the overall process.